﻿using FreeSql.Internal;
using FreeSql.Internal.Model;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;

namespace FreeSql.SqlServer {
	class SqlServerExpression : CommonExpression {

		public SqlServerExpression(CommonUtils common) : base(common) { }

		internal override string ExpressionLambdaToSqlOther(Expression exp, List<SelectTableInfo> _tables, List<SelectColumnInfo> _selectColumnMap, Func<Expression[], string> getSelectGroupingMapString, SelectTableInfoType tbtype, bool isQuoteName, bool isDisableDiyParse, ExpressionStyle style) {
			Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, _tables, _selectColumnMap, getSelectGroupingMapString, tbtype, isQuoteName, isDisableDiyParse, style);
			switch (exp.NodeType) {
				case ExpressionType.Convert:
					var operandExp = (exp as UnaryExpression)?.Operand;
					var gentype = exp.Type.NullableTypeOrThis();
					if (gentype != exp.Type.NullableTypeOrThis()) {
						switch (gentype.ToString()) {
							case "System.Boolean": return $"(cast({getExp(operandExp)} as varchar) not in ('0','false'))";
							case "System.Byte": return $"cast({getExp(operandExp)} as tinyint)";
							case "System.Char": return $"substring(cast({getExp(operandExp)} as nvarchar),1,1)";
							case "System.DateTime": return $"cast({getExp(operandExp)} as datetime)";
							case "System.Decimal": return $"cast({getExp(operandExp)} as decimal(36,18))";
							case "System.Double": return $"cast({getExp(operandExp)} as decimal(32,16))";
							case "System.Int16": return $"cast({getExp(operandExp)} as smallint)";
							case "System.Int32": return $"cast({getExp(operandExp)} as int)";
							case "System.Int64": return $"cast({getExp(operandExp)} as bigint)";
							case "System.SByte": return $"cast({getExp(operandExp)} as tinyint)";
							case "System.Single": return $"cast({getExp(operandExp)} as decimal(14,7))";
							case "System.String": return operandExp.Type.NullableTypeOrThis() == typeof(Guid) ? $"cast({getExp(operandExp)} as varchar(36))" : $"cast({getExp(operandExp)} as nvarchar)";
							case "System.UInt16": return $"cast({getExp(operandExp)} as smallint)";
							case "System.UInt32": return $"cast({getExp(operandExp)} as int)";
							case "System.UInt64": return $"cast({getExp(operandExp)} as bigint)";
							case "System.Guid": return $"cast({getExp(operandExp)} as uniqueidentifier)";
						}
					}
					break;
				case ExpressionType.Call:
					var callExp = exp as MethodCallExpression;

					switch(callExp.Method.Name) {
						case "Parse":
						case "TryParse":
							switch (callExp.Method.DeclaringType.NullableTypeOrThis().ToString()) {
								case "System.Boolean": return $"(cast({getExp(callExp.Arguments[0])} as varchar) not in ('0','false'))";
								case "System.Byte": return $"cast({getExp(callExp.Arguments[0])} as tinyint)";
								case "System.Char": return $"substring(cast({getExp(callExp.Arguments[0])} as nvarchar),1,1)";
								case "System.DateTime": return $"cast({getExp(callExp.Arguments[0])} as datetime)";
								case "System.Decimal": return $"cast({getExp(callExp.Arguments[0])} as decimal(36,18))";
								case "System.Double": return $"cast({getExp(callExp.Arguments[0])} as decimal(32,16))";
								case "System.Int16": return $"cast({getExp(callExp.Arguments[0])} as smallint)";
								case "System.Int32": return $"cast({getExp(callExp.Arguments[0])} as int)";
								case "System.Int64": return $"cast({getExp(callExp.Arguments[0])} as bigint)";
								case "System.SByte": return $"cast({getExp(callExp.Arguments[0])} as tinyint)";
								case "System.Single": return $"cast({getExp(callExp.Arguments[0])} as decimal(14,7))";
								case "System.UInt16": return $"cast({getExp(callExp.Arguments[0])} as smallint)";
								case "System.UInt32": return $"cast({getExp(callExp.Arguments[0])} as int)";
								case "System.UInt64": return $"cast({getExp(callExp.Arguments[0])} as bigint)";
								case "System.Guid": return $"cast({getExp(callExp.Arguments[0])} as uniqueidentifier)";
							}
							break;
						case "NewGuid":
							switch (callExp.Method.DeclaringType.NullableTypeOrThis().ToString()) {
								case "System.Guid": return $"newid()";
							}
							break;
						case "Next":
							if (callExp.Object?.Type == typeof(Random)) return "cast(rand()*1000000000 as int)";
							break;
						case "NextDouble":
							if (callExp.Object?.Type == typeof(Random)) return "rand()";
							break;
						case "Random":
							if (callExp.Method.DeclaringType.IsNumberType()) return "rand()";
							break;
						case "ToString":
							if (callExp.Object != null) return callExp.Object.Type.NullableTypeOrThis() == typeof(Guid) ? $"cast({getExp(callExp.Object)} as varchar(36))" : $"cast({getExp(callExp.Object)} as nvarchar)";
							break;
					}

					var objExp = callExp.Object;
					var objType = objExp?.Type;
					if (objType?.FullName == "System.Byte[]") return null;

					var argIndex = 0;
					if (objType == null && callExp.Method.DeclaringType == typeof(Enumerable)) {
						objExp = callExp.Arguments.FirstOrDefault();
						objType = objExp?.Type;
						argIndex++;
					}
					if (objType == null) objType = callExp.Method.DeclaringType;
					if (objType != null) {
						var left = objExp == null ? null : getExp(objExp);
						if (objType.IsArray || typeof(IList).IsAssignableFrom(callExp.Method.DeclaringType)) {
							switch (callExp.Method.Name) {
								case "Contains":
									//判断 in
									return $"({getExp(callExp.Arguments[argIndex])}) in {left}";
							}
						}
					}
					break;
				case ExpressionType.NewArrayInit:
					var arrExp = exp as NewArrayExpression;
					var arrSb = new StringBuilder();
					arrSb.Append("(");
					for (var a = 0; a < arrExp.Expressions.Count; a++) {
						if (a > 0) arrSb.Append(",");
						arrSb.Append(getExp(arrExp.Expressions[a]));
					}
					if (arrSb.Length == 1) arrSb.Append("NULL");
					return arrSb.Append(")").ToString();
				case ExpressionType.ListInit:
					var listExp = exp as ListInitExpression;
					var listSb = new StringBuilder();
					listSb.Append("(");
					for (var a = 0; a < listExp.Initializers.Count; a++) {
						if (listExp.Initializers[a].Arguments.Any() == false) continue;
						if (a > 0) listSb.Append(",");
						listSb.Append(getExp(listExp.Initializers[a].Arguments.FirstOrDefault()));
					}
					if (listSb.Length == 1) listSb.Append("NULL");
					return listSb.Append(")").ToString();
				case ExpressionType.New:
					var newExp = exp as NewExpression;
					if (typeof(IList).IsAssignableFrom(newExp.Type)) {
						if (newExp.Arguments.Count == 0) return "(NULL)";
						if (typeof(IEnumerable).IsAssignableFrom(newExp.Arguments[0].Type) == false) return "(NULL)";
						return getExp(newExp.Arguments[0]);
					}
					return null;
			}
			return null;
		}

		internal override string ExpressionLambdaToSqlMemberAccessString(MemberExpression exp, List<SelectTableInfo> _tables, List<SelectColumnInfo> _selectColumnMap, Func<Expression[], string> getSelectGroupingMapString, SelectTableInfoType tbtype, bool isQuoteName, bool isDisableDiyParse, ExpressionStyle style) {
			if (exp.Expression == null) {
				switch (exp.Member.Name) {
					case "Empty": return "''";
				}
				return null;
			}
			var left = ExpressionLambdaToSql(exp.Expression, _tables, _selectColumnMap, getSelectGroupingMapString, tbtype, isQuoteName, isDisableDiyParse, style);
			switch (exp.Member.Name) {
				case "Length": return $"len({left})";
			}
			return null;
		}
		internal override string ExpressionLambdaToSqlMemberAccessDateTime(MemberExpression exp, List<SelectTableInfo> _tables, List<SelectColumnInfo> _selectColumnMap, Func<Expression[], string> getSelectGroupingMapString, SelectTableInfoType tbtype, bool isQuoteName, bool isDisableDiyParse, ExpressionStyle style) {
			if (exp.Expression == null) {
				switch (exp.Member.Name) {
					case "Now": return "getdate()";
					case "UtcNow": return "getutcdate()";
					case "Today": return "convert(char(10),getdate(),120)";
					case "MinValue": return "'1753/1/1 0:00:00'";
					case "MaxValue": return "'9999/12/31 23:59:59'";
				}
				return null;
			}
			var left = ExpressionLambdaToSql(exp.Expression, _tables, _selectColumnMap, getSelectGroupingMapString, tbtype, isQuoteName, isDisableDiyParse, style);
			switch (exp.Member.Name) {
				case "Date": return $"convert(char(10),{left},120)";
				case "TimeOfDay": return $"datediff(second, convert(char(10),{left},120), {left})";
				case "DayOfWeek": return $"(datepart(weekday, {left})-1)";
				case "Day": return $"datepart(day, {left})";
				case "DayOfYear": return $"datepart(dayofyear, {left})";
				case "Month": return $"datepart(month, {left})";
				case "Year": return $"datepart(year, {left})";
				case "Hour": return $"datepart(hour, {left})";
				case "Minute": return $"datepart(minute, {left})";
				case "Second": return $"datepart(second, {left})";
				case "Millisecond": return $"(datepart(millisecond, {left})/1000)";
				case "Ticks": return $"(cast(datediff(second, '1970-1-1', {left}) as bigint)*10000000+621355968000000000)";
			}
			return null;
		}
		internal override string ExpressionLambdaToSqlMemberAccessTimeSpan(MemberExpression exp, List<SelectTableInfo> _tables, List<SelectColumnInfo> _selectColumnMap, Func<Expression[], string> getSelectGroupingMapString, SelectTableInfoType tbtype, bool isQuoteName, bool isDisableDiyParse, ExpressionStyle style) {
			if (exp.Expression == null) {
				switch (exp.Member.Name) {
					case "Zero": return "0";
					case "MinValue": return "-922337203685477580"; //微秒 Ticks / 10
					case "MaxValue": return "922337203685477580";
				}
				return null;
			}
			var left = ExpressionLambdaToSql(exp.Expression, _tables, _selectColumnMap, getSelectGroupingMapString, tbtype, isQuoteName, isDisableDiyParse, style);
			switch (exp.Member.Name) {
				case "Days": return $"floor(({left})/{60 * 60 * 24})";
				case "Hours": return $"floor(({left})/{60 * 60}%24)";
				case "Milliseconds": return $"(cast({left} as bigint)*1000)";
				case "Minutes": return $"floor(({left})/60%60)";
				case "Seconds": return $"(({left})%60)";
				case "Ticks": return $"(cast({left} as bigint)*10000000)";
				case "TotalDays": return $"(({left})/{60 * 60 * 24})";
				case "TotalHours": return $"(({left})/{60 * 60})";
				case "TotalMilliseconds": return $"(cast({left} as bigint)*1000)";
				case "TotalMinutes": return $"(({left})/60)";
				case "TotalSeconds": return $"({left})";
			}
			return null;
		}

		internal override string ExpressionLambdaToSqlCallString(MethodCallExpression exp, List<SelectTableInfo> _tables, List<SelectColumnInfo> _selectColumnMap, Func<Expression[], string> getSelectGroupingMapString, SelectTableInfoType tbtype, bool isQuoteName, bool isDisableDiyParse, ExpressionStyle style) {
			Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, _tables, _selectColumnMap, getSelectGroupingMapString, tbtype, isQuoteName, isDisableDiyParse, style);
			if (exp.Object == null) {
				switch (exp.Method.Name) {
					case "IsNullOrEmpty":
						var arg1 = getExp(exp.Arguments[0]);
						return $"({arg1} is null or {arg1} = '')";
				}
			} else {
				var left = getExp(exp.Object);
				switch (exp.Method.Name) {
					case "StartsWith":
					case "EndsWith":
					case "Contains":
						var args0Value = getExp(exp.Arguments[0]);
						if (args0Value == "NULL") return $"({left}) IS NULL";
						if (exp.Method.Name == "StartsWith") return $"({left}) LIKE {(args0Value.EndsWith("'") ? args0Value.Insert(args0Value.Length - 1, "%") : $"(cast({args0Value} as nvarchar)+'%')")}";
						if (exp.Method.Name == "EndsWith") return $"({left}) LIKE {(args0Value.StartsWith("'") ? args0Value.Insert(1, "%") : $"('%'+cast({args0Value} as nvarchar))")}";
						if (args0Value.StartsWith("'") && args0Value.EndsWith("'")) return $"({left}) LIKE {args0Value.Insert(1, "%").Insert(args0Value.Length, "%")}";
						return $"({left}) LIKE ('%'+cast({args0Value} as nvarchar)+'%')";
					case "ToLower": return $"lower({left})";
					case "ToUpper": return $"upper({left})";
					case "Substring":
						var substrArgs1 = getExp(exp.Arguments[0]);
						if (long.TryParse(substrArgs1, out var testtrylng1)) substrArgs1 = (testtrylng1 + 1).ToString();
						else substrArgs1 += "+1";
						if (exp.Arguments.Count == 1) return $"left({left}, {substrArgs1})";
						return $"substring({left}, {substrArgs1}, {getExp(exp.Arguments[1])})";
					case "IndexOf":
						var indexOfFindStr = getExp(exp.Arguments[0]);
						if (exp.Arguments.Count > 1 && exp.Arguments[1].Type.FullName == "System.Int32") {
							var locateArgs1 = getExp(exp.Arguments[1]);
							if (long.TryParse(locateArgs1, out var testtrylng2)) locateArgs1 = (testtrylng2 + 1).ToString();
							else locateArgs1 += "+1";
							return $"(charindex({left}, {indexOfFindStr}, {locateArgs1})-1)";
						}
						return $"(charindex({left}, {indexOfFindStr})-1)";
					case "PadLeft":
						if (exp.Arguments.Count == 1) return $"lpad({left}, {getExp(exp.Arguments[0])})";
						return $"lpad({left}, {getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
					case "PadRight":
						if (exp.Arguments.Count == 1) return $"rpad({left}, {getExp(exp.Arguments[0])})";
						return $"rpad({left}, {getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
					case "Trim": return $"ltrim(rtrim({left}))";
					case "TrimStart": return $"ltrim({left})";
					case "TrimEnd": return $"rtrim({left})";
					case "Replace": return $"replace({left}, {getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
					case "CompareTo": return $"({left} - {getExp(exp.Arguments[0])})";
					case "Equals": return $"({left} = {getExp(exp.Arguments[0])})";
				}
			}
			throw new Exception($"SqlServerExpression 未实现函数表达式 {exp} 解析");
		}
		internal override string ExpressionLambdaToSqlCallMath(MethodCallExpression exp, List<SelectTableInfo> _tables, List<SelectColumnInfo> _selectColumnMap, Func<Expression[], string> getSelectGroupingMapString, SelectTableInfoType tbtype, bool isQuoteName, bool isDisableDiyParse, ExpressionStyle style) {
			Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, _tables, _selectColumnMap, getSelectGroupingMapString, tbtype, isQuoteName, isDisableDiyParse, style);
			switch (exp.Method.Name) {
				case "Abs": return $"abs({getExp(exp.Arguments[0])})";
				case "Sign": return $"sign({getExp(exp.Arguments[0])})";
				case "Floor": return $"floor({getExp(exp.Arguments[0])})";
				case "Ceiling": return $"ceiling({getExp(exp.Arguments[0])})";
				case "Round":
					if (exp.Arguments.Count > 1 && exp.Arguments[1].Type.FullName == "System.Int32") return $"round({getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
					return $"round({getExp(exp.Arguments[0])}, 0)";
				case "Exp": return $"exp({getExp(exp.Arguments[0])})";
				case "Log": return $"log({getExp(exp.Arguments[0])})";
				case "Log10": return $"log10({getExp(exp.Arguments[0])})";
				case "Pow": return $"power({getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
				case "Sqrt": return $"sqrt({getExp(exp.Arguments[0])})";
				case "Cos": return $"cos({getExp(exp.Arguments[0])})";
				case "Sin": return $"sin({getExp(exp.Arguments[0])})";
				case "Tan": return $"tan({getExp(exp.Arguments[0])})";
				case "Acos": return $"acos({getExp(exp.Arguments[0])})";
				case "Asin": return $"asin({getExp(exp.Arguments[0])})";
				case "Atan": return $"atan({getExp(exp.Arguments[0])})";
				case "Atan2": return $"atan2({getExp(exp.Arguments[0])}, {getExp(exp.Arguments[1])})";
				case "Truncate": return $"floor({getExp(exp.Arguments[0])})";
			}
			throw new Exception($"SqlServerExpression 未实现函数表达式 {exp} 解析");
		}
		internal override string ExpressionLambdaToSqlCallDateTime(MethodCallExpression exp, List<SelectTableInfo> _tables, List<SelectColumnInfo> _selectColumnMap, Func<Expression[], string> getSelectGroupingMapString, SelectTableInfoType tbtype, bool isQuoteName, bool isDisableDiyParse, ExpressionStyle style) {
			Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, _tables, _selectColumnMap, getSelectGroupingMapString, tbtype, isQuoteName, isDisableDiyParse, style);
			if (exp.Object == null) {
				switch (exp.Method.Name) {
					case "Compare": return $"({getExp(exp.Arguments[0])} - ({getExp(exp.Arguments[1])}))";
					case "DaysInMonth": return $"datepart(day, dateadd(day, -1, dateadd(month, 1, cast({getExp(exp.Arguments[0])} as varchar) + '-' + cast({getExp(exp.Arguments[1])} as varchar) + '-1')))";
					case "Equals": return $"({getExp(exp.Arguments[0])} = {getExp(exp.Arguments[1])})";

					case "IsLeapYear":
						var isLeapYearArgs1 = getExp(exp.Arguments[0]);
						return $"(({isLeapYearArgs1})%4=0 AND ({isLeapYearArgs1})%100<>0 OR ({isLeapYearArgs1})%400=0)";

					case "Parse": return $"cast({getExp(exp.Arguments[0])} as datetime)";
					case "ParseExact":
					case "TryParse":
					case "TryParseExact": return $"cast({getExp(exp.Arguments[0])} as datetime)";
				}
			} else {
				var left = getExp(exp.Object);
				var args1 = exp.Arguments.Count == 0 ? null : getExp(exp.Arguments[0]);
				switch (exp.Method.Name) {
					case "Add": return $"dateadd(second, {args1}, {left})";
					case "AddDays": return $"dateadd(day, {args1}, {left})";
					case "AddHours": return $"dateadd(hour, {args1}, {left})";
					case "AddMilliseconds": return $"dateadd(second, ({args1})/1000, {left})";
					case "AddMinutes": return $"dateadd(minute, {args1}, {left})";
					case "AddMonths": return $"dateadd(month, {args1}, {left})";
					case "AddSeconds": return $"dateadd(second, {args1}, {left})";
					case "AddTicks": return $"dateadd(second, ({args1})/10000000, {left})";
					case "AddYears": return $"dateadd(year, {args1}, {left})";
					case "Subtract":
						switch ((exp.Arguments[0].Type.IsNullableType() ? exp.Arguments[0].Type.GenericTypeArguments.FirstOrDefault() : exp.Arguments[0].Type).FullName) {
							case "System.DateTime": return $"datediff(second, {args1}, {left})";
							case "System.TimeSpan": return $"dateadd(second, {args1}*-1, {left})";
						}
						break;
					case "Equals": return $"({left} = {getExp(exp.Arguments[0])})";
					case "CompareTo": return $"(({left}) - ({getExp(exp.Arguments[0])}))";
					case "ToString": return $"convert(varchar, {left}, 121)";
				}
			}
			throw new Exception($"SqlServerExpression 未实现函数表达式 {exp} 解析");
		}
		internal override string ExpressionLambdaToSqlCallTimeSpan(MethodCallExpression exp, List<SelectTableInfo> _tables, List<SelectColumnInfo> _selectColumnMap, Func<Expression[], string> getSelectGroupingMapString, SelectTableInfoType tbtype, bool isQuoteName, bool isDisableDiyParse, ExpressionStyle style) {
			Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, _tables, _selectColumnMap, getSelectGroupingMapString, tbtype, isQuoteName, isDisableDiyParse, style);
			if (exp.Object == null) {
				switch (exp.Method.Name) {
					case "Compare": return $"({getExp(exp.Arguments[0])}-({getExp(exp.Arguments[1])}))";
					case "Equals": return $"({getExp(exp.Arguments[0])} = {getExp(exp.Arguments[1])})";
					case "FromDays": return $"(({getExp(exp.Arguments[0])})*{60 * 60 * 24})";
					case "FromHours": return $"(({getExp(exp.Arguments[0])})*{60 * 60})";
					case "FromMilliseconds": return $"(({getExp(exp.Arguments[0])})/1000)";
					case "FromMinutes": return $"(({getExp(exp.Arguments[0])})*60)";
					case "FromSeconds": return $"({getExp(exp.Arguments[0])})";
					case "FromTicks": return $"(({getExp(exp.Arguments[0])})/10000000)";
					case "Parse": return $"cast({getExp(exp.Arguments[0])} as bigint)";
					case "ParseExact":
					case "TryParse":
					case "TryParseExact": return $"cast({getExp(exp.Arguments[0])} as bigint)";
				}
			} else {
				var left = getExp(exp.Object);
				var args1 = exp.Arguments.Count == 0 ? null : getExp(exp.Arguments[0]);
				switch (exp.Method.Name) {
					case "Add": return $"({left}+{args1})";
					case "Subtract": return $"({left}-({args1}))";
					case "Equals": return $"({left} = {getExp(exp.Arguments[0])})";
					case "CompareTo": return $"({left}-({getExp(exp.Arguments[0])}))";
					case "ToString": return $"cast({left} as varchar)";
				}
			}
			throw new Exception($"SqlServerExpression 未实现函数表达式 {exp} 解析");
		}
		internal override string ExpressionLambdaToSqlCallConvert(MethodCallExpression exp, List<SelectTableInfo> _tables, List<SelectColumnInfo> _selectColumnMap, Func<Expression[], string> getSelectGroupingMapString, SelectTableInfoType tbtype, bool isQuoteName, bool isDisableDiyParse, ExpressionStyle style) {
			Func<Expression, string> getExp = exparg => ExpressionLambdaToSql(exparg, _tables, _selectColumnMap, getSelectGroupingMapString, tbtype, isQuoteName, isDisableDiyParse, style);
			if (exp.Object == null) {
				switch (exp.Method.Name) {
					case "ToBoolean": return $"(cast({getExp(exp.Arguments[0])} as varchar) not in ('0','false'))";
					case "ToByte": return $"cast({getExp(exp.Arguments[0])} as tinyint)";
					case "ToChar": return $"substring(cast({getExp(exp.Arguments[0])} as nvarchar),1,1)";
					case "ToDateTime": return $"cast({getExp(exp.Arguments[0])} as datetime)";
					case "ToDecimal": return $"cast({getExp(exp.Arguments[0])} as decimal(36,18))";
					case "ToDouble": return $"cast({getExp(exp.Arguments[0])} as decimal(32,16))";
					case "ToInt16": return $"cast({getExp(exp.Arguments[0])} as smallint)";
					case "ToInt32": return $"cast({getExp(exp.Arguments[0])} as int)";
					case "ToInt64": return $"cast({getExp(exp.Arguments[0])} as bigint)";
					case "ToSByte": return $"cast({getExp(exp.Arguments[0])} as tinyint)";
					case "ToSingle": return $"cast({getExp(exp.Arguments[0])} as decimal(14,7))";
					case "ToString": return exp.Arguments[0].Type.NullableTypeOrThis() == typeof(Guid) ? $"cast({getExp(exp.Arguments[0])} as varchar(36))" : $"cast({getExp(exp.Arguments[0])} as nvarchar)";
					case "ToUInt16": return $"cast({getExp(exp.Arguments[0])} as smallint)";
					case "ToUInt32": return $"cast({getExp(exp.Arguments[0])} as int)";
					case "ToUInt64": return $"cast({getExp(exp.Arguments[0])} as bigint)";
				}
			}
			throw new Exception($"SqlServerExpression 未实现函数表达式 {exp} 解析");
		}
	}
}
